Process for the production of racemic menthol



Patented Dec. 8, 1942 a 2,304,563

UNITED STATES PATENT OFFICE PROCESS FOR THE PRODUCTION OF RACEMIC MENTHOL George Henry Gerlach, Jackson Heights, N. Y.,

and Robert S. Shelton, Mariemont, Ohio, assignors to Vick Chemical Company, New York, N. Y., a corporation of Delaware No Drawing. Application March 28, 1942, Serial No. 436,610

2 Claims. (01. 260-631) This invention relates to the production of of boiling anhydrous isopropyl alcohol. To the menthol. resulting solution is added 95 parts of 1-methyl- Various methods have been proposed for the cyclohexan-3-one, and the mixture is heated production of menthol from thymol and from in an autoclave at 220-225 C. for about 16 hours. other materials, but such processes have here- The reaction mixture is then diluted with 2500 tofore not been particularly successful because parts of water, extracted with ether, the ether of the poor yield of menthol obtained, relatively solution washed with water and then dried with large quantities of other materials, such as isoa calcium sulfate desiccant. The ether is then menthols, being produced. removed by evaporation and the residue frac- In accordance with the present invention, ra- 10 tionally distilled. The fraction boiling at 85- cemic menthol is obtained by the reaction of 100 C./8 mm. contains racemic menthol, which l-methylcyclohexan-B-one with an alkali metal, may be purified by refractionation.

e. g., sodium isopropylate. The reaction is ad- We claim:

vantageously carried out under pressure, for 1. A process for the production of racemic example in a sealed autoclave. The reaction is 15 menthol which comprises reacting 1-methylcyan oxidation-reduction process, and yields raceclohexan-3-one with an alkali metal isopropylate. mic menthol in reasonable yields. 2. A process for the production of racemic The invention will be further illustrated by the menthol which comprises reacting l-methylcyfollowing example, but it is not limited thereto. clohexan-3-one with sodium isopropylate.

Example GEORGE HENRY GERLACH. 20 parts of sodium are dissolved in 318 parts ROBERT S. SHELTON. 

